1. Field of the Invention
This invention relates to a process for the production of ketone compounds by rearrangement of epoxides in the presence of iodide ions, in which quaternary ammonium or phosphonium salts, optionally in admixture with alkali metal or alkaline earth metal iodides, are used as the rearrangement catalysts.
2. Statement of Related Art
Ketone compounds having long, optionally substituted alkyl or aryl radicals are valuable intermediate products for the chemical industry and are used, for example, as foam inhibitors or in the production of PVC co-stabilizers.
Although there are a number of methods for the production of these compounds, they are all attended by the disadvantage of considerable preparative effort. Thus, fatty ketones can be obtained, for example, by pyrolysis of magnesium salts at high temperatures [Organic Synthesis, 33, 84] or by rearrangement of the epoxides in the presence of magnesium halide etherate [J. Am. Chem. Soc., 77, 3070, 5083 (1955), J. Am. Oil. Chem. Soc., 79, 6283 (1957)].
German patent application DE 36 01 380 A1 describes a simpler process in which epoxidized fatty acid esters are rearranged into the corresponding oxo compounds in the presence of sodium iodide and polyethylene glycols at 160.degree. to 200.degree. C. However, this process has the disadvantage that it involves the use of a solubilizer and, in addition, gives poor rearrangement yields.
The object of the present invention is to develop a process for the production of ketone compounds which is not attended by any of the described disadvantages.
The present invention relates to a process for the production of ketone compounds by rearrangement of epoxides in the presence of iodide ions, in which quaternary ammonium or phosphonium salts, optionally in admixture with alkali metal or alkaline earth metal iodides, are used as the rearrangement catalysts.
In this way, epoxides can be converted into the corresponding ketone compounds with high yields in the absence of solubilizers.
In the context of the invention, the term "epoxide" is understood to encompass compounds which contain at least one oxirane group and at least six carbon atoms, at least one of the four substituents of the oxirane group being a hydrogen atom.
Compounds which can be rearranged into ketone compounds by the process according to the invention belong to the following classes:
a) Epoxides of aliphatic or cycloaliphatic monoolefins containing 6 to 30 carbon atoms, such as for example hex-1-ene, cyclohexene, oct-1-ene, cyclooctene, dec-1-ene, dodec-1-ene, cyclododecene, tetradec-1-ene, hexadec-1-ene, octadec-1-ene, oct-2-ene, oct-3-ene, oct-4-ene, dec-5-ene, dodec-6-ene, tetradec-7-ene or octadec-9-ene. Olefins containing 12 to 18 carbon atoms are preferably used as starting materials.
b) Epoxides of esters of unsaturated fatty acids containing 11 to 22 carbon atoms and 1, 2 or 3 double bonds with linear or branched, aliphatic, saturated or unsaturated alcohols containing 1 to 22 carbon atoms and 0, 1, 2 or 3 double bonds, araliphatic alcohols containing 7 to 15 carbon atoms or phenols.